She never saw the Prophet ﷺ fasting the whole month except Sha'ban which he combined with Ramadan. (Using translation from Abū Dāʾūd 2336)
عَنِ النَّبِيِّ ﷺ أَنَّهُ «لَمْ يَكُنْ يَصُومُ مِنَ السَّنَةِ شَهْرًا تَامًّا إِلَّا شَعْبَانَ يَصِلُ بِهِ رَمَضَانَ»